This invention relates generally to a device which projects the axis of a bore, cylinder, or pipe and, more particularly, to an apparatus for aligning the bore of a gun for the purpose of calibrating the gun sights.
Several prior art devices exist for the operation of a laser sighting mechanism as a gun is actually fired. Once the laser is properly sighted, the laser-aided targeting scheme effectively increases a shooter""s accuracy. Of course, a shooter must still account for the drop of a bullet as it loses velocity over distance, and for wind. However, a calibration process must first be performed which aligns the laser with the true alignment of the gun bore axis. This alignment process requires that several shots be fired so that the laser beam can be adjusted to alight on a target point that intersects the bullet path. Typically, the laser is used in conjunction with a conventional optical or iron sighting system.
Many other sighting systems exist which manage to co-align a laser beam with the gun bore axis. Then, the optical sighting system can be calibrated without the necessity of shooting, as the actual bullet path, excluding the effects of gravity and wind, can be clearly seen on a target surface. For these bore axis alignment systems to work properly, the laser must be supported so that the laser beam precisely aligns with the bore axis.
Some bore axis laser alignment systems build a laser into a simulated cartridge. However, the laser-cartridge does not always seat precisely, so that the bore alignment can be inaccurate. Further, different caliber laser-cartridges must be used for each different caliber gun which must be sighted. Each laser-bullet must also be independently powered.
Other alignment systems attempt to use a single laser for a variety of gun calibers, typically by loading an elongated laser alignment mechanism into the bore. To define a line, the laser alignment mechanism must be supported in at least two positions in the gun bore axis. The use of the muzzle is a logical point to both support and center the laser, and the body of a laser can easily be designed with a universal seating mechanism to seat in a variety muzzle diameters. Some seating mechanisms engage a tapered or conical body surface against the inside diameter of the bore. Other universal seating mechanisms form a ringlike trough to seat around the outside surface of the bore muzzle. A second support point is typically in the gun bore itself. This support point is especially critical if the first support point fits a number of bore sizes, so that it must be firmly lodged against the muzzle for proper centering of the alignment device. Thus, the problem with the second gun bore support mechanism is that it must fulfill the contradictory goals of precisely centering and seating the laser alignment device, while fitting a variety of bore diameters.
Prior art systems have solved this problem by making a laser alignment mechanism with detachable parts. A stem part of the laser mechanism, for insertion into the gun bore as the second support point, can be designed with a variety of diameters. Thus, a different diameter stem can be used for each diameter of gun bore that must be aligned. Although the laser and first (muzzle) support remains the same, a variety of stems must be maintained. As with the multiple laser-bullet solution, the number of parts required make it likely that some will be lost. Other systems reduce the number of parts by making the stem diameters deformable, so that one stem will fit in bores having very similar diameters. However, a variety of stem diameters are still required.
Even more critically, a system built of assembled parts can affect the accuracy of the laser alignment. A bore-mounted laser alignment system is not useful if the laser beam does not precisely follow the line of the bore axis. Even small differences between the alignment of the laser beam and the bore axis can seriously degrade accuracy in the process of optical sighting. Further, the error between the path of the laser beam and the actual bore axis increases as the distance between the gun and target increases.
Prior art systems typically comprise multi-piece housing which may include a laser, power supply, switch, and bore and muzzle support points. For the alignment system to work properly, the parts must be assembled in such a way that the laser beam is in consistent alignment with respect to the alignment device body axis, and that the alignment device body axis always match the bore axis. However, every part interface creates a potential laser beam alignment error. For example, if the system requires that the housing be disassembled to replace batteries, then the potential exists that the system will be misaligned every time the batteries are changed. Also, if the system requires the use of multiple stem-like parts to interface with a variety of bore diameters, then the possibility exists that the system will be misaligned every time a stem is changed. These errors can be reduced by producing parts to exacting tolerances, but rigid tolerance specifications increase the cost of the system. Alternately, the number of parts to be assembled can be minimized, but then the system may not be universal enough for use with all guns.
It would be advantageous if the axis of a bore or pipe could be sighted with a laser device, adaptable to fit into a wide variety of inside diameters.
It would be advantageous if a variety of guns, with different bore diameters, could be efficiently sighted, with the use of a single laser aligning device.
It would be advantageous if the number of parts interfaces in the alignment device could be minimized to reduce the source of potential errors and to minimize fabrications costs. To that end, a one-piece body, enclosing a laser would be effective.
It would be advantageous if the above-mentioned alignment process could be conducted in populated areas without firing a shot. Likewise, it would be advantageous if the axis sighting process could be conducted quickly.
Accordingly, an aligning device for projecting an axis is provided which can be used to align a gun""s sights with the bore axis. The aligning device comprises a one-piece body to minimize the errors inherent in assembling multiple parts, as mentioned above. The body is elongated along an axis which is aligned with the gun bore axis. The body has a proximal end in which the laser is mounted and a distal end, which is inserted into the gun bore. Between the two ends is a universal seating mechanism to form a first contact region. It is called a universal seating mechanism because it seats the aligning device in a large range of bore diameters.
A bore adapter is attached to the body distal end. The outside diameter of the adapter forms a contact region with the inside diameter of the bore. The formation of the first and second contact regions by the universal seating mechanism and the bore adapter define the alignment of the body axis.